chore: rename libs→common_libs, all bot dirs to _garage suffix, fix all path refs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

PPO_Bot_garage/tests/diag_savecheckpoint.nim

@@ -0,0 +1,31 @@
+## diag_savecheckpoint.nim — reproduce the startup+saveCheckpoint path that
+## crashes with `io_npy.nim(143, 3) `0 < t.shape.len`` under the boot server.
+## Run: nim c -d:release tests/diag_savecheckpoint.nim && ./tests/diag_savecheckpoint
+
+import std/[os]
+import arraymancer
+import "../network"
+import "../training"
+import "../weights"
+
+const weightsRoot = currentSourcePath().parentDir.parentDir / "weights"
+
+var ac = initActorCritic()
+var adam: ACAdamStates
+
+let loadResult = loadBestAvailable(ac, adam, weightsRoot)
+echo "loaded=", loadResult.loaded, " roundNum=", loadResult.roundNum
+echo "adam.initialized=", adam.initialized
+echo "adam.aw1.m.shape=", adam.aw1.m.shape, " aw1.v.shape=", adam.aw1.v.shape
+echo "adam.logStd.m.shape=", adam.logStd.m.shape
+echo "adam.aw1.t=", adam.aw1.t
+
+try:
+  saveCheckpoint(ac, adam, weightsRoot, 1)
+  echo "saveCheckpoint OK"
+except CatchableError as e:
+  echo "CAUGHT CatchableError: ", e.msg
+  echo getStackTrace(e)
+except Defect as e:
+  echo "CAUGHT Defect: ", e.msg
+  echo getStackTrace(e)